When we think of spies, James Bond comes most readily to mind. But the spying game has changed markedly since the fictional British super-sleuth entered popular conscience more than half a century ago. Espionage is now most likely to take place over the internet, where there are few regulations, insurmountable terrain does not exist and, for the most determined hacker, anything is possible. Those who are good at what they do can attack, get what information they want and steal away, without leaving a definitive trace.

The US quickly pointed to China as being behind recent on-line assaults against prominent American media organisations. Computer and e-mail systems were allegedly hacked to gain information about articles involving top leaders. The revelations have been vehemently denied by Beijing. But whatever the suspicions, the nature of the internet means that it is impossible to say with certainty who launched the attacks. There is also another truth: that it is all too easy to get information and data about others on-line.

Breaches are frequent. Just days after the US media claims, the social networking giant Twitter admitted that hackers may have accessed information on about 250,000 of its 200 million users. But there is no foolproof way to fend off threats other than going back to a non-digital way of life. In a globalised world, where convenience and development are so important, that is unrealistic. Online security, therefore, becomes a matter of defence, which involves being alert and prepared.